Mixing and dispensing apparatus for hot patching material



R. O. PLATT ET AL Oct. 9, 1962 MIXING AND DISPENSING APPARATUS FOR HOT PATCHING MATERIAL Filed NOV. 1, 1960 2 Sheets-Sheet l INVENTORS R/Cf/APO 0. PLATT 77/011445 5. 4/745 701V M aw P ATTOQ/VEVS 0 1962 R. o. PLATT ET AL MIXING AND DISPENSING APPARATUS FOR HOT PATCHING MATERIAL Filed Nov. 1, 1960 2 Sheets-Sheet 2 INVENTORS IQ/CY/AIPD 0. PLAT? THOMAS E. HAL57'0N ,WM1M

ATTORNEYS Patented Oct. 9, 1962 3,057,519 MIXING AND DISPENSING APPARATUS FOR HOT PATCHING MATERIAL Richard 0. Platt, Bethel Park, and Thomas E. Ralston,

Pittsburgh, Pa., assignors to Harbison-Walker Refractories Company, a corporation of Pennsylvania Filed Nov. 1, 1960, Ser. No. 66,511 2 Claims. (Cl. 222-195) This invention relates to apparatus for applying refractory patching material to industrial furnaces while they are hot, and more particularly to the application of the material by compressed air from a gun.

It often is desirable to be able to patch open hearth furnaces, electric furnaces and the like without cooling them. This can be done by hot refractory patching material by spraying it onto the desired areas of the furnace from a gun operating by compressed air. The material is a slurry, from which the water evaporates as soon as the slurry strikes a hot furnace, thereby leaving the refractory patching material.

It is among the objects of this invention to provide gun type apparatus for applying hot patching material, in which the gun tank can be filled directly from the mixer for the patching slurry, in which air can be entrained with the slurry in controlled amount as the slurry leaves the tank, and in which the slurry can be agitated in the tank whenever that is desirable.

In accordance with this invention, a mixer for making a patching material slurry has an outlet in its bottom, from which hangs a conduit provided with a valve. Below the mixer there is a tank that is provided with a fill opening removably receiving the lower end of the mixer conduit. The fill opening can be closed by a valve. Sealed in the top of the tank is an outlet pipe that extends down inside of the tank to a point near its bottom. The outer end of the pipe is adapted to be connected to a hose for spraying the slurry on the area of the furnace that is to be patched. For forcing the slurry out of the tank, it has a compressed air inlet provided with a valve that is adapted to be connected to a source of compressed air. The outlet pipe is provided outside of the tank with a compressed air inlet in its side, to which one end of an air conduit is connected. The other end of this conduit communicates with the tank, preferably through a valve connected with the compressed air inlet valve. Air introduced into the outlet pipe through the air conduit will be entrained in the slurry and determine the spray pattern. Also, it is highly desirable to provide the outlet pipe with a second air inlet below the one just mentioned. The second inlet normally is closed, but can be opened to receive the air conduit when the latter is disconnected from the upper inlet. At that time the outlet pipe is closed by a valve between the two air inlets so that compressed air can be blown down through the pipe into the tank to agitate its contents and keep them well mixed.

The preferred embodiment of the inventiion is illustrated in the accompanying drawings, in which FIG. 1 is a side view of the complete apparatus;

FIG. 2 is an enlarged side view of the slurry tank turned 90 from FIG. 1; and

FIG. 3 is a plan view of the tank.

Referring to FIG. 1 of the drawings, a mixer is shown mounted on an elevated platform 1, through which it extends. The mixer includes a cylindrical shell 2 having a downwardly tapered bottom 3, in the center of which there is an outlet 4. A flexible conduit 5 hangs down from the outlet and normally is closed by a valve 6. Journaled in the top 7 of the shell is a vertical shaft 8 that has radially projecting blades 9 and 10 for stirring the contents of the mixer. The upper end of the shaft is rotated from a speed reducer 12 driven by an electric motor 13. The top of the shell is provided with a door (not shown), through which the desired ingredients of the mix can be delivered to the mixer. A pipe fitting 14 mounted in one side of the shell near its top is connected to a water pipe 15. The lower part of the shell is encircled by a jacket 16, to which steam is delivered through a pipe 17 in order to heat the contents of the mixer. The necessary ingredients for the desired patching material are dumped into the top of the mixer and water is then added through the side fitting 14 to form a slurry. The mix may include finely ground refractory material which may have a chrome base or a chromemagnesite base. With this material, a suitable bonding material, such as powdered sodium silicate, is mixed. During the mixing, the slurry is heated by the encircling steam jacket.

The lower end of conduit 5 extends loosely into a fill opening in the top of the tank 20 of a compressed air gun. The upper end of the fill opening is formed by a valve 21 that can be closed after the tank has been filled with slurry from the mixer. Extending down through the center of the top of the tank to a point near its bottom is an outlet pipe 22, the outer end of which is threaded or otherwise formed for the reception of a hose 23 or the like, from which the slurry can be sprayed into a furnace that needs patching. Threaded on the lower end of the pipe, as shown in FIG. 2, is a sleeve 24 that can be screwed up or down on the pipe to vary the distance between its lower end and the bottom of the tank for best operation of the gun. The bottom of the tank is provided with a hand hole normally closed by a screw plug 25, so that the tank can be drained and the sleeve reached.

The top of the tank is provided with a compressed air inlet 26, to which a throttling valve 27 is connected. The inlet of this valve is adapted to be connected to a source of compressed air, preferably through a T-fitting 28 attached to the top of the valve. "One arm of the fitting serves as the inlet for the compressed air and preferably is provided with a throttling valve 29, to which a compressed air line 30 can be connected after the tank has been put in operating position. These two valves are Open while the tank is being filled from the mixer. T he fill valve 21 then is closed and the tank is transported by a crane or lift truck to a location near the furnace that is to be patched, and then compressed air line 30 is attached to valve 29. The opposite end of the T-fitting arm normally is closed by a throttling valve 31. The compressed air puts pressure on the slurry in the tank and forces it up through outlet pipe 22 and out into the hose, by which it is sprayed onto the parts of the furnace that are to be patched.

In order to add air to the slurry leaving the tank so that the pattern and the consistency of the slurry issuing from the hose can be controlled, one end of an air conduit 32 is connected with the tank through valve 31, the opposite end of the conduit being detachably connected to a compressed air inlet 33 in the side of outlet pipe 22 above the tank. By manipulating valves 27 and 31, the proportions of slurry and compressed air entrained in it can be regulated to suit the desires of the operator.

When the gun is not in use but its tank contains slurry, the mixture can be kept from settling by keeping it agitated. This is done by disconnecting air conduit 32 from inlet 33 and connecting it to a second normally closed inlet 34 in the side of the outlet pipe below inlet 33. The main inlet valve 27 is closed, valve 31 is opened and a valve 35 in the pipe between the two compressed air inlets is closed. The compressed air then enters the tank through the outlet pipe at the bottom of the slurry and in bubbling up through it keeps the slurry well mixed. In the same way the slurry in the mixer can be kept mixed 3 while the tank is not being filled and Without operating motor 13. Thus, valve 6 below outlet 4- can be closed and a valve 37 between them opened. The second valve is in a compressed air line 38 that will blow air up through the mixer and its contents.

With the apparatus disclosed herein, hot patching material can be prepared continuously in the mixer and supplied to the gun tank every time the tank is emptied. The tank can be carried back and forth, without any difliculty, between the mixer and the furnaces being patched. By manipulating the various valves at the tank, a workman has complete control over the slurry issuing from the application hose 23.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what We now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

We claim:

1. Apparatus for applying patching material to hot industrial furnaces, comprising a mixer for making a patching material slurry and having an outlet in its bottom, a conduit depending from the outlet, a valve in the conduit, a tank below the mixer provided with a fill opening removably receiving the lower end of the conduit, a valve for closing said opening, an outlet pipe sealed in the top of the tank and extending down inside of it to a point near its bottom, a hose connection at the outer end of the pipe, the tank having a compressed air inlet, a valve for said inlet adapted to be connected to a source of compressed air, said outlet pipe being provided outside of the tank with a pair of vertically spaced compressed air inlets in its side, a normally open valve in the outlet pipe between said pair of inlets, an air conduit communicating with the tank, and means for selectively connecting said air conduit with either of said upper and lower pipe inlets.

2. Apparatus for applying patching material to hot industrial furnaces, comprising a mixer for making a patching material slurry and having an outlet in its bottom, a conduit depending from the outlet, a valve in the conduit, a tank below the mixer provided with a fill opening removably receiving the lower end of the conduit, a valve for closing said opening, an outlet pipe sealed in the top of the tank and extending down inside of it to a point near its bottom, a hose connection at the outer end of the pipe, the tank having a compressed air inlet, a valve for said inlet adapted to be connected to a source of compressed air, said outlet pipe being provided outside of the tank with a pair of vertically spaced compressed air inlets in its side, a normally open valve in the outlet pipe between said pair of inlets, means normally closing the lower pipe inlet, an air conduit communicating with said inlet valve and having an end detachably connected to the upper pipe inlet, a valve in said air conduit, and means for detachably connecting said end of the air conduit to said lower inlet after the air conduit has been disconnected from the upper inlet.

References Cited in the file of this patent UNITED STATES PATENTS 1,047,452 Schottgen Dec. 17, 1912 1,851,044 Genovesi Mar. 29, 1932 2,015,488 Manabe Sept. 24, 1935 2,410,763 Uhl Nov. 5, 1946 2,504,009 De Phillips et al Apr. 11, 1950 3,019,058 Pro Jan. 30, 1962 

